Method of automatically controlling transfer voltage and fusing temperature in an electrophotographic printing apparatus

ABSTRACT

A method of automatically controlling an electrophotographic printing apparatus&#39; transfer voltage and fusing temperature according to the type of paper by an automatic mode change during manual paper feeding which includes the steps of following a manual feed option being selected, automatically converting the apparatus&#39;s normal paper mode into a paper selection mode in response to the manual paper feeding; and when a keyboard input is made indicating a change in the type of paper, setting the transferring voltage and fusing temperature according to the keyboard input and printing images corresponding to image data from a host computer system on the paper.

CLAIM FOR PRIORITY

This application makes reference to, incorporates the same herein, andclaims all benefits accruing under 35 U.S.C. §119 from an applicationfor Method Of Automatically Controlling Transfer Voltage And FusingTemperature In An Electrophotographic Printing Apparatus earlier filedin the Korean Industrial Property Office on 8 Mar. 1996 and there dulyassigned Ser. No. 6016/1996.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an electrophotographic printingapparatus, and more particularly, relates to a method of automaticallycontrolling transfer voltages and fusing temperatures of anelectrophotographic printing apparatus during manual paper feeding by anautomatic mode conversion.

2. Related Art

Electrophotography is widely used in computer printers, facsimilemachines and photocopiers in order to produce images on recording mediain response to video signals. A common example of an electrophotographicprinting apparatus is a laser beam printer which prints images onindividual sheet of paper through a series of electrostaticimage-forming steps. Generally, the process of electrostatic imageforming includes charging a photosensitive drum to a substantiallyuniform potential so as to sensitize the surface thereof. The chargedportion of the photosensitive drum is exposed to a light image to recordan electrostatic latent image on its surface. The latent image is thendeveloped by applying toner from a developing unit onto thephotosensitive drum which is subsequently transferred and fixed on arecording medium. When a toner image is fixed on a recording medium, thetoner image is first heated and fused onto the recording medium, andthen naturally cooled so that it is fixed onto the recording medium.

One preferred fusing method is to provide a fuser fixing device used forfixing an image on a recording medium which consists of a fuser rollerand a pressure roller. The fuser roller is typically heated to bring thepair of coactive rollers into contact with each other, thereby forming anipping and fusing section. The recording medium is passed through thisnipping and fusing section to fix the toner aligned thereon. When therecording medium is passed through the nipping and fusing section, thealigned toner which forms an image on the recording medium is heated andat the same time subjected to pressure. The heat energy and pressureapplied at the nipping and fusing section changes the shape of thetoner. This action causes the toner to be fixed onto the recordingmedium.

A significant problem in the conventional heated fuser roller systems isthe temperature variations of the heat transferred to the fuser rollsurface due to changes in the characteristics of the recording mediumsuch as paper of different size and thickness. Recent efforts in the artto cope with the fusing temperature variations in accordance with paperof different size are disclosed in U.S. Pat. No. 5,361,124 forTemperature Control System For A Fuser issued to Rowe et al., U.S. Pat.No. 5,325,166 for Fuser Overheat Control issued to Hamilton et al., U.S.Pat. No. 5,321,481 for Fuser Temperature And Copy Output Controllerissued to Mathers, and U.S. Pat. No. 5,331,384 for Fixing ApparatusHaving Temperature Controller Which Controls Temperature According toWidth Size And Number of Recording Sheets issued to Otsuka. For paper ofspecial thickness such as overhead transparency, label and envelop,traditional efforts in the art such as disclosed, for example, in U.S.Pat. No. 4,634,262 for Toner Image Fixing Control Process And ApparatusIn Electrostatic Copying Machine issued to Imaizumi and U.S. Pat. No.4,373,801 for Fixing Temperature Selecting Control In A Copying Machineissued to Itoh, require the user to set the fuser roller system at ahigher fusing temperature in a special paper selection mode to performthe fixing, or alternatively, to set the fuser roller system to aconstant lower temperature in a normal paper selection mode at which thetoner image can be fixed to thin paper so as to prevent the thin paperfrom burning. Multiple function key inputs are burdensome butnecessarily required to convert the current mode of operation betweenthe normal paper selection mode and the special paper selection mode.

Recent efforts in the art to regulate a desired fusing temperature inaccordance with variations of paper characteristics are disclosed, forexample, in U.S. Pat. No. 5,512,992 for Apparatus And Method ForControlling Fusing Temperature issued to Kim et al. and assigned to thesame assignee of the instant application, U.S. Pat. No. 5,486,903 forImage Forming Apparatus With Paper Thickness Detector issued to Kanno etal., and U.S. Pat. No. 4,439,143 for Heat Roller Fixing Device issued toHanamoto et al. In Hanamoto '143, for example, a changeover arrangementis installed to automatically change over to one of the normal paperselection mode and the special paper selection mode in accordance withthe thickness of the recording medium. In Kanno '903, a sophisticatedpaper thickness detector in a form of an air capacitor having upper andlower conductor plates is installed to automatically detect thethickness of the recording medium. Once the thickness of the recordingmedium is detected, the optimum fuser temperature is computed from thedetected thickness of the recording medium. Similarly, Kim '922 alsouses a paper thickness detector for detecting the thickness of therecording medium in order to adjust the input reference fusingtemperature to a desired value for fixing a toner image accordingthereto. While the efforts allow optimal image formation without fixingfailure, it has been my observation that the installation of paperthickness detector in combination of other control devices can be costprohibitive. Moreover, the inclusion of such a paper thickness detectorwholly deprives the user the opportunity to control manual operation ofthe system such as a manual feed option.

SUMMARY OF THE INVENTION

Accordingly, it is therefore an object of the present invention toprovide an improved printer method of automatically changing a paperselection mode and controlling a transfer voltage according to the typeof paper that is fed into the printer through a manual feed option.

It is also an objective to provide a printer and method of automaticallysetting the printer's fusing temperature corresponding to a transfervoltage preset for the type of paper when the paper is fed into theprinter through a manual feed slot.

These and other objects of the present invention can be achieved by amethod of automatically controlling a transfer voltage and a fusingtemperature in a printer according to different type of recording mediumby an automatic mode change during manual paper feeding. The methodincludes the steps of automatically converting the printer's normalpaper mode into a paper selection mode and requesting a user to makeselection of the type of recording medium usable for printing operation,in response to input of a recording medium via a manual feed section ofthe printer; and when the user selects the type of recording mediumpaper usable for printing operation via a key input, setting thetransfer voltage and fusing temperature according to the key input andprinting images corresponding to image data from a host computer systemonto the recording medium as the recording medium is being fed throughthe manual feed section of the printer.

The present invention is more specifically described in the followingparagraphs by reference to the drawings attached only by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention, and many of theattendant advantages thereof, will become readily apparent as the samebecomes better understood by reference to the following detaileddescription when considered in conjunction with the accompanyingdrawings in which like reference symbols indicate the same or similarcomponents, wherein:

FIG. 1 illustrates an exemplary laser beam printer using anelectrophotographic process;

FIG. 2 is a graphical diagram illustrating the exemplary laser beamprinter's fusing compatibility according to fusing temperature;

FIG. 3 is a block diagram of the exemplary laser beam printer; and

FIG. 4 is a chart of the control sequence of the video control unit foradjusting the printer's transfer voltage and fusing temperatureaccording to the type of paper.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and particularly to FIG. 1, whichillustrates an exemplary image forming apparatus such as a laser beamprinter using an electrophotographic process. The laser beam printerincludes a photosensitive drum 10, a charger 12, developing unit 14, alaser exposure unit 16, a mirror reflector 18, a transfer roller 20, apick-up roller 22, a convey roller 24, a pair of idle rollers 26 and 28,a pair of registration rollers 30a and 30b, a fixing unit comprising apair of coactive rollers which consists of a fuser roller 32a and apressure roller 32b, a pair of output rollers 34a and 34b, and a cleaner39. The charger 12 and the cleaner 39 are generally encased in the samehouse 42.

As shown in FIG. 1, the charger 12, creates a uniform static electriccharge on the outer surface of the photosensitive drum 10. The laserexposure unit 16 generates a laser beam L corresponding to a time-serialelectrical pixel signal of image information input from an originalimage reading unit (not illustrated), and traces the image on the outersurface of photosensitive drum 10 with the mirror reflector 18, so as tocreate a latent image on the surface of the photosensitive drum 10. Thelatent image is converted to a toner image by the developing unit 14.

The electrophotographic process begins when the pickup roller 22, picksup the uppermost sheet of paper S loaded in the paper cassette 38. Theconveyor roller 24 working with the idler rollers 26 and 28 convey thepaper to registration rollers 30a and 30b, where the paper is aligned. Atransfer charge is applied to the outer surface of the photosensitivedrum 10 by the transfer roller 20, to transfer the toner image onto thepaper. After toner image is transferred onto the paper, the cleaner 39removes any residual toner on the surface of the photosensitive drum 10,and the fixing unit fuses the toner image to the paper. The fixing unitincludes a fuser roller 32a and a pressure roller 32b. Fuser roller 32ais heated by a heat lamp to fuse the toner image to the paper S.

The laser beam printer as shown in FIG. 1 also has sensors which monitorthe operating state of the printer such as the paper conveyance state,the opening or the closing of the printer's cover. Sensors S1 to S3 areinstalled to monitor the paper conveyance state. The first sensor S1 islocated between a manual feed slot (MFS) and the second idle roller 28to monitor the status of the paper that is fed from the MFS. The secondsensor S2 is located in the paper path between convey roller 24 andregistration rollers 30a and 30b to monitor the status of the paper thatis transferred to registration rollers 30a and 30b. The third sensor S3is mounted in the paper output path between the fixing unit and paperoutput rollers 34a and 34b to monitor the state of paper discharged tothe output tray (not illustrated).

The laser beam printer has an automatic feeder and a secondary manualfeed slot. The automatic feeder is used to feed A4, B4, or letter-sizedpaper to the electrophotographic printing mechanism of the printer, andthe secondary manual feed slot is used to allow the user to manuallyfeed paper or special paper such as overhead transparencies, labels,envelopes, etc. The special paper may be thicker or even doubled thethickness of a normal paper, and can be difficult if not impossible tobe fed into the automatic feeder. Overhead transparencies, which arelarge in size and thickness have higher resistance than normal paper'sresistance. Thus, when such transparencies are used as the recordingmedia, higher voltages should be applied to them when compared to thoseapplied to the normal paper in order to produce documents with highprint quality. The printer commonly adjusts the optimum conditions ofelectrostatic printing process to normal paper printing, and where thetoner image is transferred to an overhead transparency, the density ofthe printed image decreases.

In order to enhance the print quality, it is necessary to control thetransfer voltages according to the type of paper used. The printertypically requires the user to set the fuser roller system at a higherfusing temperature in a special paper selection mode to perform thefixing, or alternatively, to set the fuser roller system to a constantlower temperature in a normal paper selection mode at which the tonerimage can be fixed to thin paper so as to prevent the thin paper fromburning. Multiple function key inputs are required to convert thecurrent mode of operation between the normal paper selection mode andthe special paper selection mode.

FIG. 2 illustrates the printer's fusing compatibility that varies withfusing temperatures in accordance with the type of paper used such asnormal paper and special paper. Curve A indicates the toner image fusionon normal paper, and curve B corresponds to the toner image fusion onspecial paper which is fed through the manual feed option. The graph'shorizontal and vertical axes correspond to fusing temperatures andfusing compatibility (%). The toner is fused to paper by heat andpressure of the fixing unit, and the loss of heat varies with thethickness of paper used. When the fusing temperature, set for normalpaper, is applied to printing on special paper, the print qualitydeteriorates. A typical laser beam printer has fusing compatibility of80% or more, where toner is satisfactorily fused to paper except coldoffset (COS) and hot offset (HOS). In other words, an appropriate rangeof the printing environment for normal paper (A) corresponds to A',where the printer's fusing temperature appropriate for normal paper is160°±15° C. In the same way, the fusing characteristics of special paperis represented by curve B, where B' represents an appropriate operatingrange where the printer's fusing temperature for the special paper is185°±10° C. Generally, in the laser beam printer that can print normalpaper A and special paper B, the printer's fusing temperature is set forthe normal paper, where the toner images are not satisfactorily fused tothe special paper. Since the printer's fusing temperature is notappropriately set for the type of paper, poor print quality oftenresults.

Referring now to FIG. 3 which is a block diagram of a laser beam printerusing an electrophotographic process according to the principles of thepresent invention. The laser beam printer includes a video control unit40, a print engine unit 50, and an operational panel OPE 48. Videocontrol unit 40 includes a computer interface 42, an image processingunit 44, and an engine interface 46. Computer interface 42 is connectedbetween a host computer and image processing unit 44 for transferringinput/output signals.

Video control unit 40 converts data from computer interface 42 intoimage data so that it can be processed by printer engine unit 50. Imageprocessing unit 44 includes a read-only-memory (ROM) containing acontrol program and a table of transfer voltages and fusing temperaturesfor different types of paper such as a thin paper, a normal paper and aspecial thick paper, and a random-access-memory (RAM) for temporarilystoring various data produced by the host computer and OPE 48. While thedifferent type of paper in the preferred embodiment of the presentinvention is characterized in terms of the paper thickness, differentpaper sizes may also be included in the control program for reliablefixing of a toner image onto the paper which is fed through a manualfeed option (MFS). Image processing unit 44 converts input data receivedby computer interface 42 into image data which can be processed byprinter engine unit 50 according to the operating program, and thensends the converted image data to the printer engine unit 50.

Engine interface 46, which is connected between image processing unit 44and printer engine unit 50, transfers input/output (I/O) signals to andfrom printer engine unit 50 under the control of image processing unit44. The OPE 48 is equipped with a set of input keys such as a paperselection key for allowing the user to make selection between theprinting of a thin paper, a standard paper and a thick paper, throughwhich control commands that are sent to the printer, and a display unitfor providing a visual display of status information during the printingoperation.

Printer engine unit 50 includes a video interface 52, an engine centralprocessing unit (CPU) 54, an input/output (I/O) interface 56, a sensorcircuit 58, a facility driver 60, and a developing unit 62, and isconnected to video control unit 40. Video interface 52 links videocontrol unit 40 with engine CPU 54. Under the control of imageprocessing unit 44, engine CPU 54 has control over facility driver 60and developing unit 62, and prints images corresponding to the imagedata from video control unit 40.

The engine CPU 54 monitors for operating failures which occur in theprinter engine unit 50 such as paper feeding, paper conveyance, etc.with the sensor circuit 58. The I/O interface 56 is connected betweenthe engine CPU 54, the sensor circuit 58, the facility driver 60, andthe developing unit 62 in order to link the engine CPU 54 with thesensor circuit 58, the facility driver 60 and the developing unit 62.The sensor circuit 58 controls sensors which monitor the operating stateof each of the components, the paper conveyance state, and the amount oftoner, and transmits output signals of the sensors to engine CPU 54. Thefacility driver 60 actuates various operating components of the laserbeam printer used for paper feeding, paper conveyance, and printingoperation. Developing unit 62 prints images under the control of engineCPU 54.

FIG. 4 is a flow chart of the control sequence of a video control unitfor setting the printer's transfer voltage and fusing temperatureaccording to the paper type such as a thin paper, a normal paper and aspecial thick paper. The following description relates to the steps ofcontrolling the printer transfer voltage and fusing temperatureaccording to the type of paper used. This control sequence is describedwith reference to FIGS. 1 to 4.

When the laser beam printer as shown in FIG. 1 is in a standby mode, theimage processing unit 44 monitors whether the manual feed option (MFS)has been selected by the user at step 70. In other words, the imageprocessing unit 44 determines if the manual feed option has beenselected by analyzing the output signal of the first sensor S1 locatedbetween the manual feed slot and second idle roller 28. When the paperis being fed into the printer through the MFS at step 70, the imageprocessing unit 44 asks the user to select the type of paper through thedisplay unit of the OPE 48 at step 72. The image processing unit 44 thenchecks if a keyboard paper selection entry has been made by analyzingthe output signal from the OPE 48. If there has been no keyboard inputfor paper selection, the image processing unit 44 proceeds to step 84,and checks for a print output command from the host computer. Upon acommand to print from the host computer, image processing unit 44 setsthe printer's transfer voltage for normal paper at step 86 and thefusing temperature for normal paper at step 88, and then allows an inputimage to be printed on paper at step 90.

Alternately, if the keyboard input for paper selection from the OPE 48has been made, the image processing unit 44 sets a transfer voltageaccording to the type of paper selected by the user at step 76. Thepaper selection key can be adjusted for the thickness (or weight) ofpaper such as thin, thick, and normal paper.

Image processing unit 44 sets the printer fusing temperature accordingto the input paper selection key of Step 74. Set values for the transfervoltage and fusing temperature according to the type of paper aredetermined by a table of value that is stored in the ROM. The imageprocessing unit 44 checks for a command to print from the host computer.Upon receipt of a print command at step 80, the image processing unit 44controls the printing operation at step 82 with the transfer voltage andfusing temperature set in step 76 and step 78. When multiple sheets ofpaper are continuously fed into the printer through the manual feedslot, the image processing unit 44 repeats step 70 and step 82.Conversely, where there is no paper fed through the manual feed slot,the image processing unit 44 automatically returns the current mode ofoperation to a normal paper mode. The normal paper default values fortransfer voltage and fusing temperature are set.

According to the present invention, the laser beam printer's mode isautomatically changed into the paper selection mode when paper is fedinto the printer through the manual feed slot thereby eliminatingmultiple keyboard entries and enhancing the operation efficiency. Whenthe laser beam printer prints on special paper which is thinner orthicker than normal, the present invention adjusts the printer'stransfer voltage and fusing temperature to be adequate for the type ofpaper, so that the best possible print quality is achieved. When theprinting operation is completed in paper selection mode, the printer'scurrent mode automatically returns to the normal paper mode to therebyavoid operational delays caused by multiple keyboard inputs. The presentinvention is also applicable to copy machines, some facsimileequipments, and other apparatus employing electrophotography.

While there have been illustrated and described what are considered tobe preferred embodiments of the present invention, it will be understoodby those skilled in the art that various changes and modifications maybe made, and equivalents may be substituted for elements thereof withoutdeparting from the true scope of the present invention. In addition,many modifications may be made to adapt a particular situation to theteaching of the present invention without departing from the centralscope thereof. For example, the type of paper can be characterized interms of the width size such as small paper (A5 sheets), full paper(81/2"×11", B5, A4 and executive sheets), and envelopes. A controlprogram as stored in the image processing unit 44 can be configured torelate optimal transfer voltages and fusing temperatures for thespecific type of paper fed into the manual feed option. Therefore, it isintended that the present invention not be limited to the particularembodiment disclosed as the best mode contemplated for carrying out thepresent invention, but that the present invention includes allembodiments falling within the scope of the appended claims.

What is claimed is:
 1. A method of automatically controlling a transfervoltage and a fusing temperature in a printer according to differenttype of recording medium by an automatic mode change during manual paperfeeding, said method comprising the steps of:when a user feeds arecording medium into a manual feed section of the printer,automatically converting the printer's normal paper mode into a paperselection mode and requesting a user to make selection of the type ofrecording medium usable for printing operation; and when the userselects the type of recording medium usable for printing operation via akey input, setting the transfer voltage and fusing temperature accordingto said key input and printing images corresponding to image data from ahost computer system onto said recording medium as said recording mediumis being fed through said manual feed section of the printer.
 2. Themethod of claim 1, further concurrently generating a visual display of amessage requesting the user to make selection of the type of recordingmedium on an operational panel when the recording medium is fed into themanual feed section of the printer.
 3. The method of claim 2, furtherdetermining whether the recording medium is fed into the manual feedsection of the printer by analyzing an output signal from a sensorlocated adjacent to the manual feed section to sense the manual feedingof the recording medium into the printer.
 4. The method of claim 3,further converting the paper selection mode back to the normal papermode, when the recording medium has not been fed into the printerthrough the manual feed section after completing the printing in thepaper selection mode.
 5. The method of claim 1, further comprised ofsaid recording medium exhibiting one of a first, second and thirddifferent thicknesses respectively corresponding to a thin paper, astandard paper, and a thick paper.
 6. The method of claim 5, furthercomprising:determining whether a print command has been input to theprinter, when there is no input of the recording medium via the manualfeed section of the printer; and setting the transfer voltage and fusingtemperature at standard values established for fixing images onto saidrecording medium exhibiting said second thickness corresponding to thestandard paper, and printing images corresponding to image data fromsaid host computer system onto said recording medium.
 7. A method ofautomatically controlling a transfer voltage and a fusing temperature ofan image forming apparatus in accordance with variations of papercharacteristics by an automatic mode conversion during manual paperfeeding, comprising the steps of:when a manual feed option is selected,displaying a message requesting input of the type of paper usable forprinting operations on an operational panel; when informationidentifying the type of paper usable for printing operations is inputthrough the operational panel, adjusting the transfer voltage and fusingtemperature according to said input; when a print command is receivedfrom an external computer system, printing images from said externalcomputer system on said paper on the basis of the adjusted transfervoltage and fusing temperature as said paper is being fed into theapparatus through a manual feed slot; and when the paper is no longerfed into the apparatus through said manual feed slot, returning thesettings of the transfer voltage and fusing temperature for normalpaper.
 8. The method of claim 7, further comprised of said paperexhibiting one of a first, second and third different thicknessesrespectively corresponding to a thin paper, a standard paper, and athick paper.
 9. The method of claim 8, further comprising:determiningwhether a print command is received from the external computer system,when there is no selection of said manual feed option; and setting thetransfer voltage and fusing temperature at standard values establishedfor fixing images onto standard paper, and printing images correspondingto image data from said external computer system onto said standardpaper.
 10. An image forming apparatus for controlling a transfer voltageand a fusing temperature for fusing a toner image on a recording mediumin accordance with variations of recording medium characteristics,comprising:means for forming a toner image on the surface of therecording medium; a fixing unit including a fuser roller and a pressureroller held in pressure contact with said fuser roller, for fixing saidtoner image on the surface of the recording medium; a manual feed slotfor allowing manual input of recording medium for image formingoperations; a paper cassette for containing a stack of recording media;an operational panel including a keyboard having a plurality of discretekeys that are independently operable by manual depression to generatedifferent control functions, and a display unit for providing a visualdisplay of operation of the apparatus; a controller for regulating afusing temperature for fixing said toner image on the surface of therecording medium in accordance with variations of recording mediumcharacteristics by:when a manual feed option is selected, providing avisual display of a message requesting selection of the type ofrecording medium usable for image forming operations on said operationalpanel; when information identifying the type of recording medium usablefor image forming operations is selected through said operational panel,adjusting the transfer voltage and the fusing temperature according tosaid selection; when a print command is received after the fusingtemperature has been adjusted for the type of recording medium selected,printing images on said recording medium on the basis of the adjustedfusing temperature as said recording medium is being fed into theapparatus through said manual feed slot; and when said recording mediumis no longer fed into the apparatus through said manual feed slot,returning to the fusing temperature previously established for fixingthe toner image on the surface of individual recording medium containedin said paper cassette.
 11. The image forming apparatus of claim 10,further comprised of said recording medium exhibiting one of a first,second and third different thicknesses respectively corresponding to athin paper, a standard paper, and a thick paper.
 12. The image formingapparatus of claim 11, further comprised of said recording mediumcontained in said paper cassette exhibiting said second thicknesscorresponding to the standard paper.
 13. The image forming apparatus ofclaim 12, further comprised of said controller comprising:determiningwhether a print command is received from a host computer system, whenthere is no selection of said manual feed option; and setting the fusingtemperature at a standard value established for fixing the toner imageon the surface of the standard paper, and printing images correspondingto image data from said host computer system onto said standard paper.14. A printer, comprising:a manual feed slot for allowing manual inputof a recording medium for image forming operations; a paper cassette forcontaining a stack of recording media; an operational panel including akeyboard having a plurality of discrete keys that are independentlyoperable by manual depression to generate different control functions;means for forming a toner image on the surface of said recording medium;a fixing unit for fixing said toner image on the surface of saidrecording medium; a controller for automatically converting, in responseto input of said recording medium via said manual feed slot, into apaper selection mode and requesting user's selection of the type ofrecording medium usable for printing operations, and for automaticallysetting a transfer voltage and a fusing temperature in accordance withsaid user's selection via said key input for said printing operations assaid recording medium is being fed via said manual feed slot.
 15. Theprinter of claim 14, further comprised of said controller furtherproviding a visual display of a message requesting selection of the typeof recording medium usable for image forming operations on saidoperational panel.
 16. The printer of claim 15, further comprised ofsaid controller automatically adjusting the transfer voltage and thefusing temperature when the type of recording medium usable for printingoperations is selected by said user via said operational panel.
 17. Theprinter of claim 16, further comprised of said controller furtherprinting images on said recording medium on the basis of the adjustedfusing temperature as said recording medium is being fed via said manualfeed slot, when a print command is received after the fusing temperaturehas been adjusted for the type of recording medium selected.
 18. Theprinter of claim 17, further comprised of said controller returning tothe fusing temperature previously established for fixing the toner imageon the surface of individual recording medium contained in said papercassette when said recording medium is no longer fed through said manualfeed slot.
 19. The printer of claim 18, further comprised of saidrecording medium contained in said paper cassette corresponding to astandard paper.
 20. The printer of claim 14, further comprised of saidrecording medium exhibiting one of a first, a second and a thirddifferent thickness respectively corresponding to a thin paper, astandard paper, and a thick paper.